MLB.com’s T.R. Sullivan is reporting Adrian Beltre has agreed to a six-year, $96 million contract with the Texas Rangers. The deal is pending a physical, and is not expected to be made official until next week.

On the surface, Beltre’s move from Fenway to Arlington is fantasy friendly, as Arlington had the sixth-highest ballpark factor in 2010 according to ESPN’s MLB Park Factor. Fenway Park was the seventh-highest.

In fact, Beltre’s career numbers at Rangers Ballpark are quite encouraging. In 51 games (219 at-bats) there, the soon-to-be 32-year-old has hit .306 with nine homers and 34 RBI.

It’s worth mentioning, however, what happened last time Beltre signed a multi-year contract.

In 2004, Beltre’s first contact year, the then 25-year-old hit .334, blasted 48 home runs and tallied 121 RBI for the Dodgers. In the following off-season, he signed a five-year, $64 million deal with Seattle.

Beltre’s fat contract seemed to weight him down in 2005, as the third basemen hit just .255 with 19 HRs and 87 RBI.

In his five years with the Mariners, Beltre never came close to putting up the monster numbers he posted in 2004, failing to top 30 HRs, 100 RBI or even a .280 batting average.

In 2009, the last season of his Seattle contract, Beltre underperformed still, hitting just .265 with eight homers while battling injuries.

Beltre landed a one-year, $10 million deal with Boston during the off-season, and became a fantasy commodity in 2010 once again. In 589 at-bats, he hit a whopping .321 (career average .275) with 28 HRs and 102 RBI.

So what should we expect from Beltre in 2011? Will the new contract hamper his desire to play? Or will his new surroundings in hitter-friendly Rangers Ballpark aid his fantasy value?

I tend to think both factors will play into Beltre’s 2011 performance. It’s important to note, however, the true cause behind Beltre’s 2010 success.

In his five years with Seattle, Beltre averaged 21 HRs, 79 RBI and a .266 batting average. His 2010 totals with Boston were: 28 HRs, 102 RBI, .321 batting average.

The spike in home runs can probably be attributed to his home ballpark (Fenway opposed to Safeco). The increase in RBI is likely due to the lineup he was in (a potent Boston offense opposed to a dismal Seattle attack).

The difference in batting average? Luck. Beltre posted a .331 BABIP in 2010, a far cry from his career mark of .294. If (and when) his BABIP drops back down into the .300 range in 2011, he’s no better than a .270 hitter with 25 HRs. Solid? Yes. Good enough for top five at a thin third-base position or an ADP of 57 on Mock Draft Central? No.